Related methods

Executes a custom SQL query against your database and returns all the
results. The results will be returned as an array with columns requested
encapsulated as attributes of the model you call this method from. If you
call Product.find_by_sql then the results will be returned in a
Product object with the attributes you specified in the SQL query.

If you call a complicated SQL query which spans multiple tables the columns
specified by the SELECT will be attributes of the model, whether or not
they are columns of the corresponding table.

The sql parameter is a full SQL query as a string. It will be
called as is, there will be no database agnostic conversions performed.
This should be a last resort because using, for example, MySQL specific
terms will lock you to using that particular database engine or require you
to change your call if you switch engines.

You can use the same string replacement techniques as you can with
ActiveRecord::QueryMethods#where:

Post.find_by_sql["SELECT title FROM posts WHERE author = ? AND created > ?",author_id,start_date]Post.find_by_sql["SELECT body FROM comments WHERE author = :user_id OR approved_by = :user_id",{:user_id=>user_id}]

# File activerecord/lib/active_record/querying.rb, line 38def find_by_sql(sql,binds=[])result_set=connection.select_all(sanitize_sql(sql),"#{name} Load",binds)column_types={}ifresult_set.respond_to?:column_typescolumn_types=result_set.column_typeselseActiveSupport::Deprecation.warn"the object returned from `select_all` must respond to `column_types`"endresult_set.map{|record|instantiate(record,column_types)}end